AEU president Angelo Gavrielatos seized on this, saying it was contrary to previous statements by Opposition Leader Tony Abbott.

"Mr Abbott thinks Australia should aim to be the number one nation in the world with a broken funding system that is sending us backwards," Mr Gavrielatos said on Wednesday.

"Mr Pyne supports the broken funding system but thinks setting a target is mad."

The draft legislation commits to a new funding system for all schools, public or private, based on need, as recommended by the Gonski funding review panel.

But it doesn't include any details about what that new structure would look like or how much it would cost.

Schools Minister Peter Garrett again defended the bill - which in its draft form includes a clause making it not legally binding.

"As we reach agreement with states and independent school sectors so we will progressively add to that legislation," Mr Garrett told the forum on Tuesday.

"But this is a clear, crystal clear indication of how fair dinkum we are about it."

He is currently negotiating with state and territory education ministers about what advice they should give to the Council of Australian Governments in December regarding the structure and money needed for any funding reforms.

At their meeting on Tuesday several ministers expressed considerable disquiet about the lack of detail given so far.

However, they did reiterate the importance of working collaboratively to further national school funding reform.

South Australian Education Minister Grace Portolesi told the AEU forum, held after that meeting, her state did "give a Gonski".

"Clearly Gonski proposes a complete remodelling of the way that we're doing this stuff," she said.

"I think that it's absolutely time that we do that but we've got to work out the details."

But The West Australian newspaper reported on Wednesday WA education minister Peter Collier had written to Mr Garrett saying his state did not support the legislation.

One of his chief criticisms was the bill as drafted did not clearly outline the commonwealth would not be seeking to take control of schools or directly fund public schools.